Cig-a-like

These are the ones from the newsagent. They are slim and white with a light on the end. The cartridge is often brown to match a tobacco cigarette. The cartridges are invariably pre-filled with a tobacco flavoured liquid. They may come with a choice of nicotine strengths and a choice of a few flavours, for example standard and menthol. In addition to the newsagent versions, there are other more up-market cig-a-likes. One hopes these have a higher quality.

A tobacco cigarette is smoked in approximately ten puffs. These market-leading e-cigarettes are only delivering between a sixth and a thirtieth of the nicotine delivered by a tobacco cigarette. That is pitiful.

Cartomiser

Now we get into the area of the separate battery. A cartomiser (a contraction of cartridge and atomiser) is identical to the cartridge of a cig-a-like, but it is sold to be refilled and it is generally sold empty. Vapers now have a choice of eliquids from whichever vendor they choose. Most eliquid still comes from China, where the e-cigarette was invented, but some companies are sourcing their ingredients locally.

Tanks

The wadding inside a cartridge must remain wet if it is not to burn and spoil the flavour, maybe permanently. A tank system wraps the cartridge in a glass tank full of liquid. The cartridge has holes punched in it to allow the liquid to penetrate. It has the advantage of a greater capacity with more constant vapour production. But it is fiddly to fill and rather expensive.

Clearomiser

This horrible term refers to a system that places the atomiser directly in the tank, removing the cartridge with its wadding. Since atomisers have a finite life, the cheap clearomisers are disposable items. At around £5 each, that is not too much expense. The more expensive ones have replaceable atomisers, with replacements costing around £2. The disadvantage is in the control of the liquid flow through the wick and onto the coil. If not enough liquid flows the coil runs dry and the flavour tastes burnt. If too much flows the coil floods, hampering vapour production and leaking liquid onto the battery below.

Clearomisers come with an atomiser either at the top or at the bottom. Both alternatives have pros and cons. A top atomiser tastes better and delivers warmer vapour, but it can run dry when the liquid level is low. A bottom atomiser is more consistent, but can flood more easily.

Rebuildable

At the top end of the market are rebuildables, where the user has to make their own atomiser by winding the coil around a silica-based wick. They generally work like clearomisers.

Genesis

This is a high-end alternative to the rebuildable. In this design, the wick is a roll of stainless steal gauze and the atomiser is built above the tank. It gives a consistent vapour with good flavour and warmth. However setting it up is even more bother than a standard rebuildable with a silica wick, and I suspect it may leak badly if left lying down.

Battery Types

Batteries too come in various guises. They can more or less be used with any of the various types of e-cigarette above. There are only a few standards for the design of the battery to atomiser connection and adapters are commonly available and dirt cheap.

Rechargable

This is a lithium battery designed for zero maintenance. You charge it with the supplied charger, you use it. Eventually, (after a year or two,) you throw it away. Generally, rechargable batteries are larger than those supplied with cig-a-likes. They are around 15mm in diameter.

Passthrough

A passthrough battery is a rechargable battery that allows you to use it for vaping while it is charging.

Variable Voltage

There is at least one1 rechargable battery with variable voltage. Varying the voltage allows the user to control the heat of the atomiser coil, which affects the flavour, the vapour production and its warmth.

MODs

These are battery holders. The batteries are commercially available Lithium batteries, which are charged in an external charger. MODs come in two varieties — mechanical and electronic. A mechanical MOD is simply a tube with a button. The battery is connected directly to the atomiser coil when the button is pressed. Electronic MODs have electronic circuitry between the battery and the atomiser. They deliver a constant voltage to the atomiser, which results in a more consistent vape. Some have the ability to alter the voltage and to measure the resistance of the atomiser coil. Because MODs have to hold batteries, they are larger than rechargables. MODs are generally 22mm in diameter.